Composite parts and structures such as those used in the automotive, marine and aerospace industries may be fabricated using automated composite material application machines, such as composite tape lamination machines and composite fiber placement machines, collectively referred to herein as tape laydown machines.
Some conventional composite material application machines, for example a flat tape lamination machine (FTLM) or a contoured tape lamination machine (CTLM), produce flat or gently contoured composite parts by laying relatively wide strips of composite tape onto generally horizontal or vertical tooling surfaces, such as a mandrel. Other conventional composite material application machines, for example, an automated fiber placement (AFP) machine, are used to produce generally cylindrical or tubular composite parts by wrapping relatively narrow strips of composite slit tape, or “tows”, collimated into a wider band, around a rotating manufacturing tool, such as a mandrel.
Tape laydown machines have been devised that employ single or multiple composite material application heads that are operated by NC (numerical control) or CNC (computer numerical control) controllers which control movement of the application heads and ancillary functions, including applying and cutting composite tape “on the fly”. In aerospace applications, these machines may be used to fabricate a wide variety of composite parts, such as, without limitation, flat spars, stringer charges, wing skins, and barrel-shaped sections, to name a few.
Composite parts of the type mentioned above may comprise multiple plies of varying thickness, complexity, and orientation. Automated application of the tape is broken down into sequences that consist of one or more ply segments of the same or different fiber orientation. All ply segments in a sequence are normally in laid before material application proceeds to the next sequence. The part is complete when all sequences have been laid. In order to control the tape laydown machine, path generation software is provided that controls the laydown of ply segments in terms of a set of courses of specified width, fiber orientation and length. The specific machine motions and head path are selected by the NC programmer based on a few simple rules, personal experience and intuition. The process of programming the machine path is more challenging where the part utilizes complex ply segments that may result in inefficient ordering, grouping and partitioning of courses within a ply.
Further complicating the task machine programming is the fact that different tape laydown machines possess differing dynamics and configurations. For example, differing machines may possess variations in acceleration, axes velocities, number of heads per machine, number of machines per lay-up cell, all of which may effect the decision of the programmer in optimizing the machine path. Additionally, there may be unique operational condition variables that may affect overall productivity, such as variations in between material cutting and material adding reliabilities, direction of travel, head turnaround motion, and other preferred operations conditions that can affect the overall machine productivity.
Once the machine paths for the courses are generated by the programmer, the NC program does not conduct any further processing to determine whether courses in line with each other should be grouped or combined into one path as a means to efficiently laydown the tape, or whether a generated course could be partitioned into individual pieces for greater laydown efficiency.
Accordingly, there is a need for a method of controlling a tape laydown machine that optimizes machine motions, reduces course-to-course, non-productive, motions and increases tape laydown efficiency for a variety of machine types. Embodiments of the disclosure are intended to satisfy this need.